Add rdoc to Gemfile.
Make UI tests run.
Add spec rake task, and make specs run (though not pass).
Remove superfluous test loader.

Loading tests is now handled by the rake task.
Move tests to a more 'canonical' location.
Use MiniTest for testing.

Requires a change in the application run test. Without this, the tests
hang. As was the case before, a way to test-drive the application still
has to be found.
Use MiniTest::Spec to merge providers spec into providers test.
Canonicalise ISBNs before comparing for test.
Allow nil as the cover url in search results.
Fix or skip remaining tests.
Add minitest to Gemfile.
Silence uninitialized value warnings.
Make about dialog be destroyed also when not debugging.

Fix is due to warning emitted by Ruby.
Cast symbol to string before module_eval'ing it.

Needed for Ruby 1.9.
Make method_missing on BookProviders safe.
Add a FIXME. Inheriting from Array leads to problems.
Fix encoding issues in Ruby 1.9.
Remove needless $KCODE setting.
Move book and book provider specs to test.
Add spaces around the % operator.